RETINAL GANGLION CELLS RAPIDLY CHANGE POLARITY

The eye communicates to the brain all the information needed for vision in the form of electrical pulses on optic nerve fibers. These spikes are produced by retinal ganglion cells, the output neurons of the retina. In a popular view of retinal function, each ganglion cell responds to a small region of interest in the visual image, and is specialized for a certain image feature within that window. When that image feature occurs, the neuron fires. Different neurons are tuned to different features, for example some ganglion cells fire when the light dims, others when it brightens. Here we show that a rapid shift in the image on the retina can cause a dramatic change in a neuron’s preferred feature. For example, a dimming-detector can briefly turn into a brightening-detector. We explore the mechanisms that implement such a switch of feature tuning, and the consequences it might have for visual processing.